In dealing with the transferring of liquid metals from a furnace by means of a crucible or ladle, there are a number of problems present in the art today. For example, when dealing with copper alloy metals, there is no other presently known automatic ladle or crucible which does not leak. Also, there is a constant problem of dross interference when the ladle is used repeatedly. Dross, otherwise known as slag forms along the inner walls, in the pouring spout of the ladle and, in particular, in the orifice of the pouring spout thereby disturbing the accuracy of the ladle when it is used repeatedly. This dross formation occurs by oxidation and the accummulation of impurities in the main body of the ladle and in the orifice during removal and introduction of the ladle into and out of the furnace. The liquid metal within the furnace contains a layer of slag or dross on its upper surface which collects in and about the entrance of the orifice thereby destroying accuracy and causing interference with operation of the ladle. Also, with dross accummulating in the orifice when the shot of metal within the ladle is discharged, dross can be entrained with the shot causing dross discharge which is also an obvious disadvantage in known ladle and crucibles. The environment which is of particular concern is in casting operations where precise shot sizes of metal are to be delivered to a shotwell or mold cavity.
It should also be kept in mind that in addition to the problem of dross build-up in the orifice area, the accuracy is also affected in those ladles which do not have proper seals to the pouring spout orifice. Repeated dripping detracts from the accuracy of the shot which is to be delivered to mold cavity. In certain instances, it is been known that the manufacturer would not guarantee operation, for example, with molten brass.
In general, there is a need for an automatic metering ladle which provides clean liquid metal each time for non-ferrous metals. The device should minimize the dripping of metal, reduce and provide means to correct for wear and errosion of the ladle parts and maintain the cleanliness of the poured metal as it is passed into the mold from the crucible or ladle. Additionally, automation is of importance and an automated crucible or ladle for accomplishing the above results would be of great advantage, particularly in the fact that it would eliminate the need for an operator to manually pour the metal.